Kabushiki Kaisha Yaskawa Denki

Takaaki Terada

Katsutoshi Yamanaka

Kenji Yamada

Eiji Watanabe

Yoshiyuki Tanaka

Yuuichi Terazono

Akira Kumagae

For an interval in which an Op-vector and a b-vector are successively output among intervals of output voltage vectors of each phase within a PWM cycle, the output times of each vector are divided by a positive integer m to find divided times of each vector, and the Op-vector and the b-vector are each alternately output for the divided time, each vector being output m times. For an interval in which an On-vector and an a-vector are successively output, the output times of each vector are divided by a positive integer n to find divided times of each vector, and the On-vector and a-vector are each alternately output for the divided time, each vector being output n times. The adoption of this method enables dispersion of the frequency component of current ripple that arises from PWM pulses ( )-( ).

Method for controlling pwm pulse

In a three-level neutral point clamping type inverter circuit which includes a positive bus line (,), a negative bus line (,) and a neutral line (,), wherein first and second IGBTs (,), (,) are connected in series between the positive bus line (,) and a phase voltage output terminal (,) and third and fourth IGBTs (,), (,) are connected in series between the negative bus line (,) and the phase voltage output terminal (,), the three-level neutral point clamping type inverter circuit further includes a first snubber capacitor (,) provided between the positive bus line (,) and the neutral line (,), a second snubber capacitor (,) provided between the negative bus line (,) and the neutral line (,), a first snubber diode (,) having a cathode coupled to the positive bus line (,) and an anode coupled to the phase voltage output terminal (,), and a second snubber diode (,) having an anode coupled to the negative bus line (,) and a cathode coupled to the phase voltage output terminal (,).

Three-level neutral point clamping type inverter circuit

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Fukuoka, Japan

Takaaki Terada